Automatic telephone system



July 7, 1925;

R. G. RICHARDSON AUTOMATIC TELEEHONE SYSTEM Original Filed Sept. 15,1919 2 Sheets-Sheet 1 N N "a v f w jrzdenfoz July 7, 1925. 1,545,066

R. G. RICHARDSON AUTOMATIC TELEPHONE SYSTEM Original Filed Sepfc. 15,1919 2 Sheets-Sheet To OPRS H540 SET WJWWM,

Patented July 7, 1925.

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IRQDNEY Gr. RICHARDSON, OF EDISON PARK, ILLINOIS, ASSIGNOR T0 AUTOMATICELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

AUTOMATIC TELEPHONE SYSTEM.

Application filed September 15, 1919, Serial No. 323,718. RenewedNovember 3, 1924.

To all whom 2'25 may concern:

Be it known that I, RODNEY G. RrcrmnnsoN, a citizen of the United Statesof America, and a resident of Edison Park, county of Cook, and State ofIllinois, have invented ertain new and useful Improvements in. AutomaticTelephone Systems, of which the following is a specification.

My invention relates in general to automatic telephone systems, but ismore particularly concerned with means for giving measured service insuch systems; and the chief object is to provide new principles andmethods of operation, together with suitable apparatus and circuitsembodying these principles, thereby affording a more desirable andeflic-ient measured service sys tem than has hitherto been available.Other objects of the invention relate to the substation and exchangeequipment and circuits therefor; and while such improvements areespecially valuable in connection with a measured service system, it isconceived that they may be of utility in other systems not so limited.

The embodiment of my invention shown herein is a paystation or coincollecting apparatus for use in automatic telephone systems. Apparatusof this general character has been used for a long time and numeroustypes have been designed, all of which include a mechanism forcollecting coins associated with an automatic substation, together withsome arrangement whereby the calling subscriber is compelled to deposita coin for each successful call. As referred to these prior systems, asuccessful call means a call that has been answered. So far as known acall must be paid for ever Y time a connection is extended to anotherstation and a response is secured, whether the desired number isobtained or not; and the calling subscriber has no redress in case hegets the wrong number through faulty operation of the switchingapparatus, because of wrong directory numbers, or by some othermischance not his fault. In manual systems where the operator collectsthe coin, a calling subscriber who gets the wrong number can explain hisdifliculty to the operator, and in a proper case can have his coinrefunded; but hitherto auto matic systems have not included this featureand consequently have not been as successful as they might have been.

My invention cures the objection above outlined and the preferred methodof operation is as follows:

The substation is normally completely operative for outgoing calls aswell as for incoming calls. This means that a connection can beestablished and conversation can be held without dropping a coin, or inother words, payment is deferred until the service is completelyrendered. lVhen the receiver is hung up at the calling station, however,it is disabled for further use so far as calling another subscriber isconcerned, and a coin must be deposited toagain render it operative.Ordinarily the subscriber will do this at once, as there is no object inhis delaying payment, although it will be seen that in an emergency,with no coin available, a connection can still be obtained and can bepaid for later on. Suppose now that on account of some defect or otherthe calling subscriber gets the wrong number. He will of course hang upthe receiver to release the connection, but will be unable to call thenumber over again because of the disabled condition of his call sender.Not wanting to drop a coin for a call that was in reality unsuccessful,and through no fault of his own the subscriber now presses a button withwhich his instrument is provided and removes his receiver. As a resultof this operation an idle finder switch at the exchange is set in motionand connects the subscribers line in question with a trunk lineextending to an operators position. The operator is provided with meansfor restoring a station thus trunked to her position to normal conditionfor calling, and in ordinary cases will do so, being free to use herjudgment, however, and require the deposit of a coin, as is the practicein 0rdinary manual systems. The system may also be operated as a systemrequiring the subscriber to pay before completing a connection bypermitting the first call from a sub-.

station to be completed free, or by the equipment being renderedinoperative upon 111; stallation so that a coin must be deposited 7Further features and details of operation will bedescribed hereinafter,reference be ing had to the accompanying drawings, in which there isshown diagrammaticallythe essential parts of an automatic telephone sysem embodying the inve ntion.

Preferdn'g to the drawings, which should be placed in order withcorresponding lines at the ends thereof in alignmenuFig. #1 shows at theleft a substation A which includes talking equipment, a calling device Sfor controlling the automatic switches at the exchange, and coincollecting apparatus, together with relays and circuits for effect ingthe cooperation of the different elements. At the right of Fig. 1 thereis shown anindividual rotary line switch or trunk selector O, which islocated at the exchange and whose function it is to connect the line ofsubstation A, when-calling, with a trunk line extending to an idleselector switch.

One of. the trunk-lines to which the line switch C has access is-shownextending to the selector switch H (Fig. 2), which is one of a group ofsimilar switches adapted to extend-calling linesto idle trunk linesleading to desired groups of connector switches.

()ne of these latter trunk lines is shown terminating inthe connectorswitch I,-shown .only in part, which is adapted to complete connectionsto any oneof a group of sub scribers lines, one of which is thelineextending to substation A.

The trunk line which terminates in the selector H has a branch shown atthe left of Fig. 2 which is multipled in the banks of a group of finderswitches. One of these linder switches is indicatedby the referencecharacter F, and; as shown is adapted to calling device, and the line,finder, selector,

and connector switches referred to herein are in general well known inthe art, and in order tocbviate the necessity of'a lengthy descriptionreference is made to the following' patents:

British patent to Dicker, #29554 of U. S. patent to Lamb, #1,193,160,granted Aug. 1, 1916.

U. S. patent to Powell, #1,308,553, granted July 1, 1919.

U. S. patent to Keith, Erickson, and Erickson, #815,321, granted March13, 1906.

U. S. patent to Keith, Erickson and Erickson, #815,176, granted March13, 1906.

U. S. patent to Newforth, ail-13,901, reissued April 13, 1915.

The operation of the system is as follows:

Assuming that the subscriber at substation A desires to secureconnection with the subscriber at substation A, he'will first remove thereceiver B (Fig. 1) from the hook after which he will operate hiscalling Reissue *device S in accordance with the digits in the numberassignedto substation A. Upon the'removal of the receiver, a circuit iscompleted for the line relay 30 of the rotary line switch C as follows:ground at G resting contact of armature 36 and the said armature, lineconductor 26, normally closed contacts of push button P at thesubstation, armature 10 and its resting contact, im-

pulse springs 5 and 1 of the calling device S, winding of the polarizedrelay 6, transmitter T, receiver R, the working contact of the hookswitch 1, lineconductor 25, armature-37 and its resting contact, and thewinding of the line relay to battery.

. Theline relay is operated by closure of the,

above circuit and u .on attractin its arma- P e ture 3 1 completes acircuit for the switching relay 31 as follows: ground at G,

armature 8i and its working contact, windmg of relay 31, mterruptercontact of the motor magnet '32, and the winding of the said motormagnet to battery. At the same time that this circuit is closed theprivate or test wiper 39 is connected to the circuit at a point midwaybetween the relay 31 and the magnet 32 over the following path; testwiper 39, armature 35 and its resting contact, armature 33 and itsworking contact, and thence to junction point 50. The

operation now depends upon whether the trunk line with which the wipersof line switch C are associated is or is not busy, in which former casethe test contact 42 will have a ground potential upon it. Under thesecircumstances relay 31 will be shortcircuited in an obvious manner andwill not energize. At the same time the rotary magnet, being suppliedwith direct ground via the testwiper and the busy test contact, willoperate to advance the switch wipers to the next set of contacts; andsince the magnet interrupts its own circuit, this movement will continueuntil the test wiper .39 engages an idle and ungrounded test contact,when the motor magnet will cease operating. It should be mentioned herethat relay 01 is of such high resistance that the motor magnet will notenergize in series with it. Relay 31, being no longer shortcircuitedwill then energize at once. In the present case we may assume that thetrunk line shown is idle and that the test contact 42 therefore isungrounded. This being the case, upon the energization of line relay 30,no operation of the motor magnet will take place, and relay 31 willenergize immediately. By the attraction of armature 35 the test wiper 39is connected to ground G, wherebythe trunk is instantly made busy toother line switches; and by the attraction of arinatures 37 and 36, lineconductors and 26 are disconnected from the line relay 30 and ground,respectively, and are extended by way of wipers 38 and 10, bank contacts41 and d3, conductors 4 1 and 10, armatm'es 112 and 108 of relay andtheir resting contacts, armatures 113 and and their resting contacts,the upper and lower windings of line relay 102 of selector ll, and theupper and lower windings of relay 103 to battery and ground Grespectively.

The calling line having been extended by the line switch G as describedabove, relays 102 and 103 of the selector H will energize in series overthe calling subscribefis loop. Relay 103, upon attracting its armature118 opens the starting circuit of the finder switch F and associatedfinder switches to prevent the starting 01? an idle finder switch atthis time; while the line relay 102 at its armature 117 closes anenergizing circuit for the slow acting relay 10 1. Relay 104, uponenergizing, opens the circuit of the release magnet 127 at the restingcontact of armature 121; prepares a circuit for the vertical magnet 128at the working contact of the same armature; opens the finder switchstarting circuit previously mentioned at an other ooint at the restingcontact of armature and closes a holding circuit extending back to theline switch G which may be traced as follows: ground at G workingcontact of armature 119 and the said armature, conductor 170, contactspring 110, contact spring 111, conductor 15, bank contact 42, testwiper 39, armature 35 and its working contact, winding of relay 31 ofthe line switch G, and the winding of the motor magnet 32 to battery. Abranch of the above circuit extends by way of private normal conductor28 to multiple test contacts in the banks or connector switches whichhave access to the line of substation A, whereby the said line is madebusy to incoming calls. It is understood that the holding circuit justdescribed is established before the slow acting line relay 30 of lineswitch C has had time to deenergize.

The calling subscriber will now operate his calling device in accordancewith the first digit in the number of substation A, thereby producing inthe well known manner a series of interruptions in the line circuit,resulting in a. corresponding series 01 deenergizations of the relays102 and 103 of the selector H. During the operation of the callingdevice the shunt springs 2 and 3 are closed in the well known manner tobridge the calling device directly across the line and excluding thepolarized relay 6 and the talking instrumentalities R and T from thecircuit. The deenergizations of relay 103 caused by the interruptions ofthe line circuit are of no efiect at this time, for the finder switchstarting circuit is held open by the slow acting relay 101 which retainsits armatures attracted while impulses are being received. Relay 102,however, at each deenergization sends an impulse to the vertical magnet128 over the following path: ground at G armature 117 and its restingcontact, resting contact of armature 116 and the said armature, armature121 and its working contact, low resistance winding of slow acting relay105, and the winding of the vertical magnet 128 to battery. In responseto these impulses the vertical magnet 128 operates to raise the selectorshaft step by step until it arrives at the bank level in which terminatethe group of trunk lines which extend to the desired group of connectorswitches. The slow acting relay 105 is energized in series with thevertical magnet and retains its armature attracted while the latter isbeing operated. At the first upward movement of the switch shaft theofifnormal spring closes its contact, whereupon a circuit is completedfor the line switching relay 101 which may be traced as follows: groundat G, working contact of armature 119 and the said armature, con ductor170, winding of the relay 101, armature 124 and its resting contact,otinormal spring 125 and its working contact, and the winding of relay106 to battery. Relay 101 is not energized over the above circuit,however, ;tor since relay 105 is in operated position at this time,ground G is connected di rect by way of armature 122 and its workingcontact to the ottnormal spring 125, whereby it will be clear that relay101 is short-circuited. Relay 106 energizing at once upon the closure ofthe ofifnormal contacts, locks itself to the ground at its armature 173, and at its armature 123 prepares a circuit ior the rotary magnet 107.t the end of the series of impulses relay 105 deenergizes and closes acircuit which extends from ground G by way of the working contact ofarma ture 119 and the said armature, armature 122 and its restingcontact, armature 123 and its working contact, and the winding of therotary magnet 10'? to battery. The rotary magnet 107 is thereuponenergized to rotate the circuit of the rotary magnet 107, which upondeenergizing in turn, again completes the circuit including relays 101and 106. The operation now depends upon whether the test contact withwhich the test wiper 131 is in engagemiit is busy or is notbusy.

If this test contact is busy it will be grounded, relay 101 will beshort-circuited as before and relay 106 will again be energized,resulting in another closure of the circuitof the rotary magnet 107andthe consequent advance oi theselector wipers another step. The rotarymagnet thereupon interrupts the circuit of relay 106 as before, fromwhich it will be seen that the rotation will continue as long as thetest wiper continues to engage busy test contacts, the relay 106operating as a stepping relay in conjunction with the rotary magnet 107.When the test wiper 131 arrives at a nonbusy or ungrounded test contact,which we will assume is the test contact 151, and-the rotary magnet 107deenergizes, relay 106 will not again energize, owing to the highresistance of the switching relay 101; and this latter relay, being nolonger short-circuited, will energize. Upon energizing, relay 101 opensthe release magnet circuit at its armature 116; shifts the connection ofthe test wiper 131 from its own upper terminal to its lower terminal atarmature 11 i; and at armatures 113 and 115 disconnects the incomingline conductors from the windings of the line relay 102 and extends themby way of wipers 130-aiid 132, bank contacts 150 and 152, the normallyclosed sets of contact springs of the reversing relay 1Y3 oi theconnector I to the upper and lower windings, respectively, of the linerelay 154.

Upon the extension of the line circuit as above described, relay 154 isenergized over the calling subscribers loop, and upon attracting itsarmature, completes a circuit for the slow acting relay 155. Relay 155,upon energizing, closes a holding circuit for the selctor H and the lineswitch C as follows:

ground at G", conductor 171,-test contact 151, test wiper 131, andarmature 11 1 and its working-contact to the junction .point 172, wherethe circuit divides; one branch extending by way of winding of relay 101and the winding of relay 106 to battery,and the other branch extendingby way of contact rent flow in the calling line. the polarized relay 6at substation A, which hitherto has remained inoperative, is now hiscalling device in accordance with the two final digits in the callednumber. As a re sult two more series of interruptions are produced inthe line circuit, causing two corresponding series of deenergizations ofthe line relay 154-. The line relay 154 operates to controlthe connectorswitch I through the medium of its vertical and rotary magnets to.establish connection with the line of substation A. Since the operationof the connector I is well known and is sutficiently described in thepatents previously referred to, the operation will not be described indetail. It will 81111106 to say that upon the completion of theconnection the'bell at substation A" is automatically operated to signalthe called subscriber, who upon lifting his receiver from the hook,connects his substation talking equipment across the line and therebycloses an energizing circuit for the back bridge relay 153 at theconnector. Relay 153 has the usual function of a back bridge relay in aconnector switch of this general character, that of reversing theincoming line conductors as regards their con- .nections to the windingsof the line relay 154, thereby reversing the direction of our- As aresult,

energized inthe proper direction to enable it to operate its armature 9which is locked by engagement with armature 10, and which when fullyoperated prepares acircuit for the high resistance relay 7.

The connection. between the calling and called subscribers has now beenestablished and they may converse as desired. The talking circuitthrough the automatic equipment is shown in heavy lines and will bereadily understood. It will be noted that the path for voice currentsincludes the condenser at the substation, which is-connected in parallelwith the winding of the'polarized relay 6.

When thesubscriber-sarcthrough talking they will both hang up theirreceivers. lVhen the receiver is hung up at substation A the linecircuit extending through the line switch Gand selector switch ll to theline relay 15% of the connector is in terrupted and the said relay isperina- .nently deenergized, resulting in thedeenergization of the slowacting relay Relay 155, upon retracting its armatures,

causes the-restoration of the connector I to normal position in the wellknown manner and at the-same time removes ground from the holdingcircuit extending back to the selector H and the lineswitch C. At theselector-switch the line "switching relay 101 is now deenergized toclose a circuit for the release magnet .127 which operates to restorethe selector switch to normal position, its own circuit beinginterrupted at ofinormal spring 126 when the shaft returns to i nonormal. it the line switch C relay 31 deenergizes to disconnect the lineof substation A from the trunk line. At substation A, when the receiverhook reaches its lowest position it comes into engagement with itsresting contact and connects the high resistance relay 7 in bridge ofthe line as follows: line conductor 25, switch hook 1 and its restingcontact, armature 9 and its working contact, winding of high resistancerelay '7, and the normally closed contacts of the push button P to theline conductor 26. Relay '4" is energized at once but is of such highresistance that it does not interfere with the deenergization of theline relay 154 of the connector I and the subsequent release of theautomatic switches.

' llpon energizing, relay 7 attracts its arma .ture 10, which is held inoperated position by the engagement of the pin 14 with the tooth 15 ofthe escapementcarried on the arm 12 of armature 11. The attraction ofarmature 10 causes the unlocking or release of armature 9, but it shouldbe explained that these armatures are so adjusted that armature 9 is notreleased until the pin 1a of armature 10 has passed the point of tooth15 of the escapement, thus insuring that armature 9 will not be unlockedunless by the same operation armature 10 is retained by the escapeinent.As a further result of the operation of armature 10, the lower lineconductor 26 is disconnected from the branch path to the transmitter Twhich extends through the calling device springs 5 and at and thepolarized relay 6 and is connected instead to another branch or;-cluding the said calling device which passes through the windings of thepolarized relay 8. r'"\ Since the connection was en *cessfullyaccomplished the sub scribe'r at substation A will now proceed to payfor by depositing a suitable coin, 5 cents for example, in the coin slot16. As the coin passes down the coin chute it en gages the end of thearm 12 which projects into the coin chute and thereby actuates theescapenientto release the pin 14 on armature 10, permitting the saidarmature to return to normal position. It will be seen now that thesubstation A is in its original condition and is ready to establishanother connection.

The foregoing describes the ordinary operation of the system. Let it beassumed now, that by some mischance, when the line of substation A wascalled, connection was accidentally established with some other line.The operation will be the same as has been. insu t d rt that 1 190.11.the c01 pletion of the talking connection the calling subscriber willlearn at once that he has the wrong number, whereupon he will so informthe answering subscriber and will hang up his receiver to release theconnection. When the receiver is replaced, substation A. is renderedinoperative for automatic calling by the switching of the circuit atarmature 10 of relay 7, as has been just described, and it will beapparent that ordinarily the subscriber would be forced to depositanother coin before he could proceed further. However, means areprovided for remedying this evil and its operation will now beexplained.

When the subscriber finds himself in a predicament of this kind, he willpress the push button P, and while holding it depressed, will againraise the receiver from the hook, after which the push button may bereleased. The resistance r at substation A may be of about 1.000 ohmsand its inclusion in the line circuit by the reason of the separation ofthe push button springs when the receiver is removed has no effect onthe line switch C, which operates as usual to extend the line ofsubstation A intoconnect-ion with an idle trunk line, assumed, asbefore, to be the trunk line extending to the selector H. lVhen the linecircuit is extenoed to the line relays 102 and 103 of selector H theformer relay energizes, but relay 103, which is of relatively lowresistance and is marginally adjusted, does not energize, with theresult that before the slow acting relay 10st attracts its armature 120a circuit is closed over the starting wire 133 for a brief interval asfollows: ground at G armature 117 and its working contact, armature 118and its resting contact, armature 120 and its resting contact, conductor133, and the lower winding of relay 138 to battery. Relay 138 isenergized and completesa locking circuit for itself as follows: groundat G, working contact of armature 119 and the said armature, conductor170, conductor 134, upper winding of relay 138, and armature 140 and itsworking contact to battery. As a further result of the energization ofrelay 138, ground G is disconnected from the test contact 1 14; and itsmultiples in the banks of the group of finder switches of which finderswitch F is one, and a circuit for starting the operation of one ofthese finders is completed over the following path, it being as sumedthat the finder switch F is idle at this time: ground at G armature 139and its working contact, common starting wire 146, armature 210 and itsresting contact, and the winding of the line relay 211 to battery. Uponthe closure of the above circuit, line relay 211 is energized, and atits armature 215 completes an energizing circuit for slow acting relay213; and also at the same armature completes a, circuit Which may betraced through the windings of high resistance switching relay 205 andthe motor 1nagnet 212 in series to battery. Simultaneous with theclosure of this latter circuit the test wiper 203 is connected by theoperation of armature 214 to a point midway between the winding of relay205 and the motor magnet 212. The ope-ration now depends on whether thetest contact with which the test wiper 203 is in engagement is groundedor is not grounded. If the trunk line associated with this test contactis busy the test contact will have ground potential on it, relay 205will be short-circuited, and the motor magnet, which is arranged tointerrupt its own circuit, will operate as a buzzer to advance thefinder switch wipers 201 201 inclusive, in search of the calling line.

But in the present case we may assume that the wipers of finder switch Fwere standing on the set of contacts in which terminates the branch ofthe trunk line in use when the operation of the said finder wasinitiated, as shown in th drawing. Under these circumstances, sinceground has been disconnected from test contact 1 141:, the switchingrelay .205 will energize immediately following the energization of theline relay 211. The motor magnet 212, as is well understood, does notoperate because of the high resistance of relay 205. Upon the operationof relay 205 numerous circuit changes are brought about: At armature 210the starting wire 1 16 is shifted from the line relay 211 to thearmature 216 of the slow acting relay 213, whence it is connected to thestarting wire 217 extending to the next tinder switch when this latterrelay deenergizcs; at armature 208 the test wiper 203 is disconnected;while at armatures 206 and 207 the line wipers 201 and 202 are connectedto the trunk conductors 230 and 231 which extend to the equipment 0 atan operators position. Asa further result of the energization ofswitching rela 205, a circuit is completed at armature 209 for the relay100 in the trunk over the foll wing path: ground at G, armature 215 andits left hand working contact, working contact of armature 209 and thesaid armature, wiper 2041,

bank contact 145, conductor 135, and the winding of relay 100 tobattery. Upon energizing, relay 100 at its armature 109 substitutes thegrounded conductor 135 for the grounded conductor 170 in theholdingcircuit extending back to the line switch C; and at its armatures112 and 108 disconnects the incoming trunk conductors 4A and l6 from thewindings of the line relay 102 of selector H and connects them insteadto the branch trunk conductors 137 and 130, respectively, whence theymay now' be traced via the bank contacts 1 12 and 1 13, line wipers 201and 202, armatures 206 and 207 of the relay 205 (now energized),conductors 230 and 231,

and normally closed contact springs of the key K to the upper and lowerwindings, respectively, of the double wound relay 220 at the operatorsposition. Relay 220 is thereupon energized and at its armature 222completes an energizing circuit for the slow acting relay 221. Thislatter relay, upon attracting its armature 223, connects ground G to theholding circuit via conductor 232, whereby relays 205, 100, and 31 aremaintained energized after the slow acting line relay 211 has retractedits armature 21.5.

Returning now to the selector H, when the trunk conductors eat and 16are disconnected from the line relay 102 by the energization of relay100, the line relay deenergizes and opens the circuit of slow actingrelay 101, which upon decnergizing an instant later, closes the circuitof the release magnet 12'? to restore the selector to normal; and at thesame time removes ground Gr from conductor 170, thus breaking thelocking circuitof relay 138. This relay accordingly deenergizes, removesground'from the starting wire 146,'and connects ground to the testcontact 1 14 again. It is noted that relay 138 deenergizes to groundtest contact 203 before the slow acting relay 213 of the finder switchcan retract its armature 216, thus insuring that thetrunk line will bemade busy before another finder switch can be started. 7

The foregoing operations have all occurred responsive to the actuationof the push button P at the substation A. coincident with the removal ofthe receiver, and have resulted in the extension of the line circuitthrough the medium of the line switch C and the finder switch F to anoperators position, certain of the equipment therea-t being representedby the reference character 0, as previously mentioned. To proceed withthe explanation, when the line relay 211 of the finder switch F wasenergized to start the finder switch, ground G was connected by way ofconductor 232 and normally closed springs of the listening key K to thelamp L, which is thus lighted to notify the operator that a call hasbeen received. As soon she perceives the sig nal, the operator willactuate her listening key K thereby opening the lamp circuit andconnecting her head set across the line for conversation.

At substation A, when the subscriber hears the operator on the line,hewill tell her the facts in regard to his unsuccessful attempt toobtain a connection by the use of his dial, and an experienced operatorwill usually be able to tell at once whether the subscriber is entitledto a rebate or not. Failures due to calling wrong directory numbers, andthose which appear to be due to some defect in the central olliceswitches, will obviously be suflicient ground for a rebate withoutquestion on the part of the operator. Other cases will arise which aredoubtful and if she desires the operator can check up on the callingsubscribers number and then after remitting the charge, can enlist theaid of a service observer who will be able to detect habitual attemptsto defraud the company. Since this, however, is more of a trafiic detailwith which we are not particularly concerned, the explanation will be'profeeded with. In the present case, the subscriber being properlyentitled to a rebate, the operator will actuate the key K momentarily,whereby the conductors 230 and 231 are reversed as regards theirconnections to the windings of the double wound relay 220. As a resultthe direction of current flow in the line circuit is reversed and thepolarized relay 8 at substation A. is energized in the proper directionto enable it to operate its armature 11. The function of the escapementis to prevent the release of armature 10 before the reversing key isrestored to normal by the operator as otherwise the polarized relay (3would be operated also. When the current is reversed and relay 8responds to actuate its armature, the pin 14 is held by the tooth 13 ofthe escapement, which is understood to be set somewhat to the rear oftooth 15, until the current again changes its direction upon the releaseor the reversing key and armature 11 is restored. It will be seen nowthat the polarized relay 8 performs the same function as does thedeposit of a coin, that is, the restoration of substation A to normalcondition for automatic calling.

The calling subscriber will now hang up his receiver to disconnect fromthe operator. "When the line circuit is opened, relays 220 and 221 atthe operators position will deenergize. By the deenergization of thelatter relay, ground G is disconnected from the holding circuit,whereupon relays 205,

100, and 31 will simultaneously deenergize and the switching apparatuswill be ready tor another call.

lVhile not strictly necessary, it is deemed advisable to provide asignal preferably in the form of a semaphore or target controlled by thearmature 10 as shown, in order to advise the subscriber at all timeswhether his telephone is in condition for automatic calling or not.

lVhile I have described my invention in connection with a specific typeof substation equipment or paystatien, and utilizing certain specifictypes of automatic switches at the central oliisie; I recognize thatother types of switches may be used, and that the invention in itsbroader aspects is applicable to systems employing other types ofmeasured service equipment, or even to systems which are not measuredservice, but wherein it is desired that the subscribers be given readyaccess to operators without having to manipulate their dials. I do notwish to be limited, therefore, to the precise circuits and apparatusshown herein, but desire to include and have protected by Letters Patentall -t'orms of my invention which come within the scope of the appendedclaims.

What I claim is:

1. In a telephone system, a subscribers line, a trunk line having twobranchesfan automatic switch for extending one of said branches to anoperators position, a second automatic switch for extending the otheroi? said branches toward another snbscribers line, means for connectingsaid first line when calling with said trunk line, separate controllingdevices for said switches, respectively, at the substation on thecalling line, and a measured service device cooperating with one of saidcontrolling devices to count the connections established viarsaid secondswitch.

2. In a telephone system, subscribers lines, an operators position and agroup of trunk lines at the exchange for connecting said linestherewith, a second group of trunk lines for use in interconnecting saidsubscribers" lines, a station on one of said lines comprising separatecalling devices for controlling connections over the two groups of trunklines, respectively, and measured service mechanism cooperating with oneof said calling devices for requiring the subscriber to pay forconnections with other subscribers lines.

In a telephone system, subscribers lines, an operators position,subscriber controlled automatic switching mechanism at the exchangewhereby a calling subscriber can extend his line to said operator or toanother subscribers line, a measured service device at the station oneach of said lines for charging the subscriber with outgoing calls toother subscribers lines, and operator controlled mechanism at eachstation for remitting the charge on any call.

4. In a telephone system, a calling and a called line, automaticswitches at the central oflice controllable by the subscriber on thecalling line for connecting said lines, measured service mechanism atthe station on the calling line for requiring the subscriber to pay foreach. connection, an operators position accessible to the calling line,and mechanism under control of the operator for remitting the charge onunsuccessful connections.

5. The combination, in an automatic telephone system comprisingsubscribers lines and automatic switches controllable thereover toconnect said lines in conversation, of measured service mechanism at thestation on one of said lines, whereby the subscriber thereat is chargedfor each connection, in-

dependent switching mechanism controlled by said subscriber forextending connection to an operator in case any connection isunsuccessful, and means controlled by the operator for remitting thecharge.

6. In a telephone system, a plurality of: subscribers lines andautomatic switches controllable t-hereover to connect said lines inconversation, measured service mechanism at the station on one of saidlines controlling outgoii'ig calls and requiringthe subscriber to payfor each connectionbefore he can obtain a second connection, independentcalling means at said station not controlled by said mechanism, andother switches at the exchange responsive to said independent callingmeans for extendingv connections to an operator.

7. In a telephone system, a calling subscribers line, a trunk lineextending to an operators position, a second line, automatic switchescontrolled by the subscriber on the calling line for completingconnections with said second line, charging means requiring the callingsubscriber to pay for all con nections so extended, other switchesoperable by the calling subscriber independent of said charging meansfor connecting his line with said trunk line, and charge refunding meansfor rebating the charge on any connection.

8. In a telephone system, comprising subscribers lines and automaticswitching mechanism at the exchange for connecting calling and calledlines in conversation,

measured service equipment at the station on each line for assessing acharge against the subscriber there-at for each outgoing call, anoperators position, means controlled by a calling subscriber forextending a connection to the operators position without charge, andoperator controlled means for rebating the charge against such subscriber on a previous unsuccessful call.

9. In a telephone system, a calling subscribers line, an operatorsposition and other subscriber-S lines, automatic switches by thesubscriber.

separately operable at the option of the calling subscriber forconnecting his line with the operators position or with one of saidother lines, means requiring the subscriber to pay for calls to saidother lines, and operator controlled means for rebating the charge incase the desired line is not obtained.

10. In a telephone system, a calling. and a called line, automaticdirectively controlled switches for connecting said lines, automaticmeans for charging the calling subscriber for outgoing calls, anoperators position at the exchange, and operator controlled means forremitting the charge on unsuccessful calls. I

11. In a telephone system, a calling sub scribrs line, other.subsci'ibersUines, auto;-

matic switches at the exchange for connecting the calling line with adesired one of said other lines, a calling device at the station on thecalling line for controlling said vswitches, mechanism at the callingstation for rendering said calling device inoperative after every call,effective to charge the subscriber with a call and manually operable torestore said calling device to operative condition, another callingdevice at the call ing station independent of said mechanism, anautomatic trunking switch at the exchange responsive thereto to extendthe calling line toan operators position, and operator controlled meansfor restoring the said first calling device to operative positionwithout charging the subscriber with a call.

12. In a telephone system, a calling subscriber's line, other lines,automatic switches at the exchange for connecting the calling line witha desired one of said other lines, a calling device at the station onthe calling line for controlling said switches, mechanism at the callingstation for rendering said calling device inoperative after every call,coin controlled means for restoring said calling device to operativecondition, a circuit controller at the calling station independent ofsaid mechanism, an automatic trunking switch at the exchange responsivethereto to extend the calling line to an operators position, and meanscontrolled by the operator for restoring said calling device tooperative condition.

13. In an automatic telephone system, a substation including a callingdevice for controlling the switches at the exchange, means for renderingsaid calling device inoperative when the receiver is replaced after anoutgoing call is completed, manually operable means effective to chargethe subscriber with the call and at the sametime restore said callingdevice to operative condition, and a relay adapted to be controlled byan operator for restoring said calling device to operative conditionwithout payment 14. The combination, in a telephone system, of a callingsubscribers station and line extending to a central exchange, a secondline, automatic switchesfor connecting said lines, a normally operativecalling device at the calling station for controlling said switches, andmechanism controlled by the replacement of the receiver at the callingstation for rencering said calling device inoperative.

15. The combination, in a telephone system, of a calling subscribersstation and line extending to a central exchange, a second line,automatic switches for connecting said lines, a normally operativecalling device at the calling station for controlling said switches,mechanism controlled by the Ill) replacement of the receiver at thecalling station for rendering said calling device inoperative, and coincontrolled mechanism for again restoring said calling device tooperative condition.

16. The combination, in a telephone system, of a calling subscribersstation and line extending to central exchange, a second line, automaticswitches for connecting said lines, a normally operative calling deviceat the calling station for controlling said switches, mechanismresponsive to the replacement of the receiver at the calling station forrendering said calling device inoperative, said mechanism being normallyineifectual, and means controlled by the response of the calledsubscriber for rendering said mechanism efiectual.

17. The combination, in a telephone system, of a calling subscribersstation and line extending to a central exchange, a second line,automatic switches for connecting said lines. a normally operativecalling device at the calling station for controlling said switches,mechanism responsive to the replacement of the receiver at the callingstation for rendering said calling device inoperative, said mechanismbeing normally ineffectual, means controlled by the response of thecalled subscriber for rendering said mechanism effectual, and coincontrolled mechanism for again restoring said calling device tooperative condition.

18. The combination, in a telephone system, of a calling subscribersstation and line extending to a central exchange, a sec- 0nd line,automatic switches for connecting said lines, a normally operativecalling device at the calling station for controlling said switches,mechanism controlled by the replacement of the receiver at the callingstation for rendering said calling device inoperative, coin controlledmechanism for again restoring said calling device to operativecondition, an operators position accessible to the calling line whilesaid calling device is inoperative, and operator controlled means forrestoring said calling device to operative condition without payment bythe subscriber.

19. The combination, in a telephone sys tem, of a calling'subscribersstation and line extending to a central exchange, a second line,automatic switches for connecting said lines, a normally operativecalling device at the calling station for controlling said switches,mechanism responsive to the replacement of the receiver at the callingstation for rendering said calling device inoperative, said mechanismbeing normally inefiectual, means controlled by the response of thecalled subscriber for rendering said mechanism effectual, coincontrolled mechanism for again restoring said calling device tooperative condition, an operators position accessible to the callingline while said calling device is inoperative, and operator controlledmeans for restoring said calling device to operative condition withoutpayment by the subscriber.

20. In a telephone paystation, a plurality oi, controlling relays, twoparallel branch circuits each including one of said relays, a batteryteed circuit for the transmitter including one or the other of saidbranches, and a switching device for substituting one branch for theother in said circuit.

21. In an automatic telephone paystation, a plurality of controllingrelays, a calling device for controlling the automatic switches at theexchange, two parallel branch circuits, one including one of said relaysand the other including another of said relays and the said callingdevice in series, a battery feed circuit for the transmitter includingone or the other of said branches, and a switching device for substituting one branch for the other in said circuit.

22. In a telephone paystation, a plurality of controlling relays, twoparallel branch circuits each including one of said relays, a batteryfeed circuit for the transmitter including one or the other of saidbranches, a switching device for substituting one branch for the otherin said circuit, and a condenser permanently connected in the talkingcircuit so as to be in shunt of whichever one of said branches isincluded therein.

23. In an automatic telephone paystation, a plurality of controllingrelays, a calling device for controlling the automatic switches at theexchange. two parallel branch circuits, one including one of said relaysand the other including another of said relays and the said callingdevice in series, a battery feed circuit for the transmitter includ ingone or the other of said branches, a switching device for substitutingone branch for the other in said circuit, and a condenser permanentlyconnected in the tall:- ing circuit so as to be in shunt of whicheverone of said branches is included therein.

24. In a telephone system, a substation including a calling device,automatic switches at the exchange controlled by said calling device forestablishing telephone connections. measured service apparatus forcharging the subscriber with connections so established, another callingdevice at said substation, and automatic switches at the exchangeresponsive only to said second calling device.

25. In a telephone system, a calling subscribers line, a second line.subscriber con trolled automatic switches at the exchange for connectingsaid calling line with said second line, a normally operative callingdevice at the station on the calling line for Ill) controlling saidswitches, means for rendering said calling device inoperative afterevery successful call, subscriber controlled charging means adapted whenactuated to render said calling device operative, and a signal forindicating to the subscriber whether his calling device is operative orinoperative. I

26. In a telephone system, a subscribers station and line extending to acentral exchange, an automatic switch at the exchange for use inextending said line, a controlling device at he station for said switch,and ircuit connections wherebvthe said switch is prevented IIQliiresponding unless the subT scriber takes oil his receiverwhile said controlling' ,device is being actuated.

27. In a telephone system, .a substation and line extending" to acentral exch 9, independently operable circuit controlling devices atsaid station connected in series with each other and the two conductorsof said line, an automatic switch at the exchange responsive to a firstone of said devices while the second device is in normal position, and asecond automatic switch con trolled by cooperation of both said devicesand responsive to the first device when and only when the second deviceis maintained in operated position.

28. In a telephone system. a subscribers line, a trunk line at theexchange comprising two normally connected sections, the see ond ofwhich terminates in an automatic switch a branch of said trunk lineextending from the junction of said sections to a second switch, forextending a connection over said trunk via said first switch whilemaintaining; said second switch in normal position, and subscribercontrolled means for disconnecting said sections and for connecting thefi st section to said branch for extending: a con-- nection via saidsecond switch.

29. In a telephone system, a line. a

branched trunk line at the exchange having a normally connected and anormally disconnected branch at the divided end thcrcot.

each branch terminating in an automatic switch, means for connectingsaid line with the undivided end of said trunk line. a callme device atthe station on said line for con trolling the switch associated with thesaid normally connected branch, and a second calling device at saidstation effective when operated to actuate the switch associated withthe said normally disconnected branch and to connect said branch to thetrunk line in place of the other.

30. In a telephone system, line, a trunk line at the excl'iange having;two branches at one end, one branch terminating in an. automaticselector switch and the other in the bank of a finder switch, means forconneeting said line with said trunk line the subscriber controlledmeans.

undivided end thereof, independent controlling; devices atthe station onsaid line for operating said switches separately, and a switching devicefor disconnecting the branch terminating in said selectorswitch and forconnecting the branch terminating in said tinder switch whenever thelatter is operated.

The .fQlllblDAtlOIl, in an automatic telephone system comprisingsubscribers lines and automatic directively controlled connectingswitches at the exchange, of mu tomatica-lly operated means individualto each station for charging outgoing calls to the subscriber thereat,and operator controlled refunding means individual to each station forrebating the charge on unsuccess'ful calls.

' The combination, in an automatic telephone paystation, ofautomatically operated charging means, whereby the subscriber isrequired to pay for successful calls, operator controlled refunding;means for rebatingr the charge on unsuccessful calls, and automaticswitches at the .exchange directively controlled by the subscriber forsetting up connections.

33. In a telephone system, sul'iscrihers lines, measured serviceapparatus at the station on each line, automatic first selector switchesat the exchange operable in establishing talking connections only undercon trol of said apparatus and other automatic switches at the exchangeoperable independcut of said apparatus.

In a telephone system, a subscribers line extending to a centralexchange, coin collecting mechanism at the station on said line,automatic first selector switches at the exchange controllable from saidstation in establishing talking connections only when coins aredeposited in said mechanism, and other automatic switches at theexchange controllable from said station without depositing coins.

In a telephone svsteni, automatic switches for connecting calling; andcalled lines, measured service equipment for each line for charging foroutgoing calls, means for releasing established connections, an opcrators position, automatic switches for extending any calling line tosaid position after a previously established connection has beenreleased, and operator controlled means for rebating the charge againstsuch line if the previous connection was unsucccsstul.

3 6. In a telephone systen'i, automatic switches for connecting callingand called lines, measured service apparatus for each line controlledover called lines when connections are established for charging suchconnections to the calling lines, an operators position,'meanswherebyany calling subscriber can release an unsuccessful connection andextend his line to said position, and operator controlled mechanism forre bating the charge.

37. In a telephone system, a calling and a called line, automaticswitches for connect ing said lines, paystation mechanism on the callingline controlled over the called line to require the calling subscriberto pay for the connection, an operators position, means whereby thecalling subscriber can release the connection and cause his line to beconnected with said operators position, and means whereby the operatorcan control said mechanism to rebate the charge on the previousconnection.

38. In a telephone system, a calling and a called line, automaticswitches for connecting said lines, a calling device at the callingstation for controlling said switches, paystation mechanism controllingsaid calling device and requiring the calling subscriber to pay for theconnection before another connection can be established, an op eratorsposition, means whereby the calling subscriber can extend his line tosaid position after releasing the previous connection, and means wherebythe operator can control said mechanism to permit the subscriber toestablish the next connection. free of charge.

89. In a telephone system, automatic switches controllable by a callingsubscriber for extending a connection to a called line, paystationmechanism on the calling line for requiring the calling subscriber topay for each connection so established, means whereby the callingsubscriber can notify an operator at the exchange in case any connectionis unsatisfactory, and means whereby the operator can then control thesaid mech anism so as to enable the subscriber to make the next callfree of charge.

4:0. The combination, in a telephone paystation, of automaticallyoperated charging means for assessing calls against the subscriber,means responsive to payment of assessed charges for restoring thecharging means, and means for restoring the charging means withoutpayment to rebate the charge on unsuccessful calls.

41. The combination, in an automatic telephone paystation, ofautomatically operated charging means adapted to discriminate between ananswered and unanswered call and assess the former against thesubscriber, whether the right party was secured or not, means responsiveto payment of the assessed charge for preparing the charging means tohandle the next call, and independent means operable without 'paymentfor preparing the charging means to handle the next call. whereby thecharge may be remitted if the last call was unsuccessful.

42. In an automatic telephone system,

means comprising automatic directively controlled switches forconnecting calling and called lines, means consisting solely ofautomatic non-directive switches for connecting calling lines with anoperators switchboard, and measured service equipment operatingautomatically to charge the calling subscribers for the calls to otherlines but not for the calls to the operators switchboard.

In a telephone paystation, charging means operable to require thesubscriber to pay for a connection, a magnet controlled over the linefrom the exchange, means for receiving coins, and means responsiveeither to the energization of said magnet or to the deposit of a coinfor restoring said charging means.

44. In a telephone paystation, two polar relays, the first of which isnormally connected in the line circuit extending to the exchange, and athird relay energized over the line for substituting the second of saidpolar relays for the first.

45. The combination with a subscribers station and a line extending tothe exchange, of a calling device included serially in the line circuitfor controlling the exchange switches, and a relay energized over thesaid line for disconnecting one side of the call ing device from theline and for closing the line over a new path.

46. In a telephone paystation for use in automatic telephone systems, acalling device for controlling the automatic switches at the exchange,and a relay energized over the line from the exchange for opening thecircuit of said calling device to render it ineffective.

47. In a telephone paystation, three magnets all adapted to be energizedover the line from the exchange, locking means for the first magnetcontrolled by the second magnet, and locking means for the second magnetcontrolled by the third magnet.

48. In a telephone paystation, two relays and a magnet, all adapted tobe energized over the line from the exchange, means for locking thefirst relay when energized, means for locking the second relay whenenergized and for unlocking the first relay, and means for unlocking thesecond relay when the magnet is energized.

49. In an automatic telephone system, a-

subscribers station including-a calling device for controlling theautomatic switches at the exchange, measured service equipment capableof rendering said device inoperative in order to make the subscriber payfor his connections, and a visual indicator at said station for advisingthe subscriber whether the calling device is operative or not.

50. In a telephone system, a subscribers station including two manuallyoperable line circuit controlling devices, a line for said stationextending to the exchange, a backward selecting line finder switch forextending said line and starting means for said finde1- 'esp0nsive onlyto the simul taneous operation of both said devices.

51. In a telephone exchange system, calling lines, paystations for saidlines, called lines of two classes, means for extending Signed atChicago, county of Cook and State of Illinois, this 13th day of Sept,1919.

RODNEY G. RICHARDSON.

